When constructing two-story suburban cottages and summer cottages, it is necessary to observe the norms and standards in all construction processes, including the installation of staircases. The greatest load in them falls on the steps. From the parameters of these elements depends on the comfort and duration of operation of interfloor marches. Below we will talk about the acceptable range of sizes of stairs in the house, providing convenient and safe operation.
The size of the stairs according to GOST
The standards take into account all the nuances of the construction and use of transitional structures of the following types:
- interfloor;
- basements;
- attic.
- evacuation.
Interfloor home stairs can be of the following types:
- direct;
- rotary;
- screw;
- cross-country.
According to the joint venture “Residential single-family houses”, the slope, width and height of the steps of stairs in private houses should “ensure the convenience and safety of movement”, “the width and slope of the stairs are not regulated”.
As you can see, there is no direct indication of the size of the steps. That is, in fact, these parameters are not strictly standardized. However, there are generally accepted rules based on experience: the standard height of the stairs should be within 15–25 cm, and the depth should be 25–30 cm.
For attic, folding, basement options, exceeding the norms of standard options is allowed. These models are rarely used, their installation location is often limited, so the height of the steps can be higher, and the width is narrower. Designs of this purpose are often non-standard. When setting up a march in the attic or in the basement, consider that it should be convenient not only to rise, but also to descend.
Requirements for the sizes of steps of evacuation ladders
Stairs for fire evacuation are in every building, including in individual residential buildings. This type of structure has special requirements.
In evacuation marches, the installation of:
- screw and race options;
- different sizes of stairs;
- curvilinear structures;
- wooden elements.
Requirements for emergency staircases are prescribed in the joint venture “Fire protection systems. Evacuation routes and exits ”:
- the depth of the steps of the straight staircase is not less than 25 cm;
- the depth of the steps of a spiral staircase is at least 18 cm in the middle;
- riser height - no more than 22 cm;
- allowable slope - not more than 45 °;
- the number of steps in one march - from 3 to 18 pcs.
We recommend that in all private houses, the construction of the main stairs must be guided by the above requirements for the size and number of steps.
From the point of view of current standards in individual residential buildings, such restrictions are excessive. But in fact it is they who guarantee you the convenience and safety of using the stairs.
Ergonomic staircase size
The most important element of the transitional structures are steps. When calculating the ergonomics of the stairs to the second floor, take into account:
- step of steps and march slope;
- tread depth;
- riser height;
- tilt angle.
Step of steps and stairs
The step length is calculated based on the standard person’s step length - 60-64 cm. The value of the stair step (LS) is equal to the sum of the step depth (GS) and the height of two risers (VP). The total amount for a convenient design should be between 60-64 cm.
Universal convenience formula: LS = GS + 2VP = 60-64 cm.
The slope of the stairs is calculated as the ratio of the height of the span to its length. For a normal model, it should be in a ratio of 1: 2, respectively. Classic ergonomic sizes - 15x30 cm.
Moving along such a design, a person will not feel discomfort, will not lose his usual step. The standard tilt angle does not make you strain, raise your foot high.
Tread depth
The depth of the step should ensure a comfortable location of the foot on the surface, not be too small so that the foot does not hang down and not be too large so that the sole does not "drown" on the step. This parameter is included in the overall dimensions and affects the length and height of the structure.
The optimal choice is considered to be a width within 25-30 cm. This is the average size of a person's foot. To save material and make movement more comfortable, the gap between the treads is left open. Such a move allows you to conveniently place the foot on the step, without fear that it will hang or slide.
Riser height
The admissible size of the riser is in the range of 15-25 cm. This distance between the steps ensures a convenient and safe movement on the march. Even if an open space between the treads is planned, the height between them must comply with existing standards.
For the entire staircase, the riser height should be the same.
Descent and ascent should be comfortable and safe. Small size will lead to a mincing gait. High altitude will make movement difficult. When calculating the riser height, the step formula is taken into account. If the standard is not met, the design will become uncomfortable.
Span width
The optimal span is considered to be 90-120 cm, the minimum - 80 cm. Ascent and descent along the march should be convenient and provide free passage for 2 people. If it is planned to lift bulk cargo to the second floor, then the width is planned to be larger.
In the “goose pitch” models, it is possible to set a smaller width due to the fact that the steps have an uneven size. This option is often used for attics and basements. Less commonly mounted as a floor lift.
The distance between the treads is made large, but during installation they are installed in a checkerboard pattern so that the person steps on the left and right steps in turn. This allows you to keep comfortable movement and makes the march narrow.
Online calculator for calculating
An online staircase calculator makes it easy to calculate march sizes. It allows you to make quick and correct selection of the necessary parameters. To do this, substitute your values in the formula and get an answer.
You can verify the correctness of the data using the above formula.
Spiral Stair Options
Screw interfloor options due to their compactness are popular in cottages with a small area. They save space. But establishing such models, take into account the age of those living in the house. It is difficult for children and elderly people to travel on such marches.
For spiral models, the angle of inclination is not taken into account. But such options have their own standards that must be respected. In a screw design, the width of the outside of the tread is greater than the inside. The permissible minimum of the inside is 10 cm. The maximum outside is 39 cm. The minimum allowable width of the spiral staircase is 80 cm.
In such structures, risers are rarely installed, but the step height should be equal along the entire length, convenient and ensuring safety.
Runway Requirements
The rung ladder steps are in the form of a trapezoid or a truncated triangle. The depth of the tread is variable. At the base it is minimal, in the outer part it is large. With unequal parameters of the depth of the tread, the riser height remains the same.
For the width of each fragment, the norms of SNiP determine the minimum size: at the base - 10 cm, outer - not more than 40 cm.
Street constructions
The parameters of street steps differ from internal analogues. This applies to elements located at the entrance to the building, as well as on the site. Often not only direct, but also rotary options are installed outside. The rotation angle is 90 °, 180 °, sometimes arbitrary. This makes the entrance to the building convenient and accessible from any direction.
Porch models are often made of reinforced concrete. They are distinguished by reliability and durability. Parameters are selected depending on the local landscape, the design of the house.
In such cases, a more gentle slope of the stairs is allowed. At low steps it is more convenient to move, a person feels confident and without a railing. The size range is as follows:
- depth of a step - 25-40 cm;
- riser height - 15-25 cm.
As a material for outdoor structures, not only reinforced concrete, but also stone and wood are used. For outdoor installation, wood is treated with special solutions that give resistance to moisture, temperature extremes, pests. Metal products are coated with anti-corrosion compounds.
By combining the requirements of state standards and individual conditions, you can get a convenient, reliable and safe design.